Method of Certifying Transmission, Reception and Authenticity of Electronic Documents and Related Network Unit

1. A method of certifying transmission, reception and authenticity of electronic documents between at least one sender user and at least one addressee user in a telecommunication network, the method comprising: wherein the sender user carries out the following steps: drafting the document to be sent, sending a message comprising the drafted document to a mailbox associated with the addressee user through the telecommunication network, wherein the addressee user carries out the following step: downloading the message from the mailbox associated with the addressee user, and the method further comprising: receiving the message from the sender user at a certification entity, identifying by the certification entity the sender user from whom the message is received, checking at the certification entity if the sender user is a certified sender user included among sender and addressee users comprised in at least one file unit so as to admit or refuse the message, wherein a transmittal certificate is automatically generated and sent to a mailbox associated to the sender user by a certification entity connected to the telecommunication network when the message reaches the mailbox of the addressee user, if the identified sender user is included among the sender and addressee users in the file unit of the certification entity, and providing by the addressee user to the sender user one of a manual and automatic transmission of a certificate of having read the message, when the addressee user opens the message.

2. The method according to claim 1 , wherein checking if the sender user is a certified sender user included among sender and addressee users includes checking, if an identification code of the sender user is comprised in the at least one file unit.

3. The method according to claim 1 , wherein the sender user further carries out the following steps: encrypting the document to be sent, and codifying the encrypted document using a private key of the sender user, wherein the message further comprises: the document having been encrypted and codified, and a public key of the sender user, wherein the public key is associated to the private key of the sender user, and wherein the addressee user further carries out the following step: decrypting the document having been codified using the private key of the sender user by using the public key of the sender user.

4. The method according to claim 1 , wherein providing the automatic generation of a delivery certificate that is automatically sent to the mailbox of the sender user when the addressee user gains access to the mailbox associated to him.

5. The method according to claim 1 , further comprising the following steps: checking size of the document, calculating costs of the transmittal of the message, and billing the calculated costs to one of the sender user and the addressee user.

6. The method according to claim 1 , wherein a private key and a public key are supplied by a certification entity of the identity of the sender and addressee users, the keys identifying univocally the sender and addressee users.

7. The method according to claim 1 , wherein encryption and decryption operation of the document are based on a method of asymmetric cryptography.

8. A network unit operable to carry out the method of claim 1 , the network unit operating as a certification entity, the network unit comprising: connection means for connecting to a telecommunication network; reception and transmission means for receiving and transmitting messages from and to the telecommunication network; a first file unit including data of sender and addressee users, wherein the first file unit includes at least an identification code for each of the sender and addressee users; encryption and decryption means for encrypting and decrypting the messages sent and received by the reception and transmission means; identification means for identifying the sender user of a message received as input from the reception and transmission means and for checking, if the sender user is a certified sender user included among the sender and addressee users comprised in the first file unit so as to admit or refuse the message; a second file unit including the admitted messages; and certification means adapted to generate a certification document of one of transmittal and reception of the messages to one or more addressee users, if the sender user is included among the sender and addressee users.

9. The network unit according to claim 8 , further comprising an electronic mailbox associated with the sender and addressee users.

10. The network unit according to claim 8 , further comprising means for calculating costs of transmittal of a message to be charged to one of the sender user and the addressee user.

11. The network unit according to claim 8 , further comprising automatic billing means for billing the cost of transmitting a message to one of the sender user and the addressee user.

12. The network unit according to claim 8 , further comprising means for supplying a fixed time and date of reception of the message and transmission of the certificate upon request of the certification means.

13. The network unit according to claim 8 , further comprising a third file unit including the certificates.

14. The network unit according to claim 8 , wherein the first file unit of the sent documents is non-erasable.

15. The network unit according to claim 8 , wherein the third file unit of the certificates is non-erasable.

16. The network unit according to claim 8 , further comprising means for generating a copy of a message sent by the sender user.

17. The network unit according to claim 8 , wherein the means for calculating the costs of transmittal of a message further comprises means for measuring a size of the message and for cooperating with the means for identifying the requested service, and further comprising a fourth file unit including invoices.

18. The network unit according to claim 8 , further comprising means for sending SMS messages to a cellular phone of the addressee user that are automatically activated to advise the addressee user of the status of his electronic mailbox.

19. The network unit according to claim 8 , further comprising means for sending voice messages to a telephone set of the addressee user that are automatically activated to advise the addressee user of the contents of his electronic mailbox.

20. A computer operable to carry out the method of claim 1 , the computer comprising: connection means to a telecommunication network cooperating with transmission and reception means of a message; and encryption and decryption means of the messages sent or received by the transmission and reception means.

21. The computer according to claim 20 , further comprising means for handling and filing the certificates received by the certification entity.